Charge forming device



Oct-.- -1'8, 1932. J. l. ANsoN CHARGE FORMING DEVICE Filed Oct. 20, 1928 NNW VJEROME I. ANsoN, or DAYTON, omo, AssIGNoa, BY MESNE ASSIGNMENTS, 'ro DnLco Patented Oct. 18, 1932 vvUNITED PATENT OFFICE@ PRODUCTS CORPORATION, O F DAYTON,`OHIO, vA C0RPORA'.I,[ONk 0F DELAWARE y CHARGE FORMING DEVICE Application led October 20, k1928. Serial No. 313,83?.

This invention relates to charge forming devices for internal ycombustion engines and more particularly to the type of charge form.-

ing device which comprises a plurality of primaryinixing chambers, each of which is adapted to deliver a primary mixture of air and fu'el to one of a` pluralityof secondary mixing chambers, one of which is associated.

No. 221,372, filed September 22, 1927, which matured to Patent 1,819,526 granted Aug. 18, 1931, and Fred E. Aseltine and Wilford H; Teeter, Serial No, 221,371, filed September 22, 1927, which. matured to Patent 1,819,495 granted Aug. 18,1931. f Y

In earlier Vdevices of thistype, such as those disclosed in the above mentioned applications, various means have been provided to control the kflow of fuel and air under various different operating conditions to secur-e at all times a mixture having the desired fuel and air ratio. Among the proportion-y ing means employed in-these earlier devices is a means for admitting air to the primary mixing chambers in' advance of the fuel jet to reduce the velocity lofflow past the jet and prevent a tendency to provide an overrich mixture as the engine speed increases, such an air admitting means being disclosed in the above mentioned application of Wilford H. Teeter, Serial No. 221,372'. This air admitting ymeans in the devices heretofore known was controlled wholly bythe size of the air passage or passages and the pressures effect-ing flow` therethrough and has, not proved entirely satisfactory in its operation, as it has been found Vdesirableto varythe mixture proportions under certainoperating conditions, and for this purpose ytopincrease the effective suction on the Jets.

The present invention relates primarily to a charge forming device of the type shown in Y the abovementioned Teeter application and its principal object is to provide a means to prevent enrichment of the mixture under certain operating conditions, which is automatically controlled in lits action to provide an enriched mixture under other operating con-..

ditions to supply the increased' power which these operating conditions demand.` More specifically, it is anobject of the invention to provide` means for admitting air to the mixturepassage posterior-to the jet to prevent- Y mixture enrichment, and to provide means for reducing the admission of such air as the en- -gine speed increases, in order to enrich the mixture at high engine speed.

These Vobjects are accomplished according to the present invention by the provision of passages admitting air `to the primary mixture passages between the nozzles and the out-` leten'ds ofrsaid mixture passages. These air passages terminate adjacent the primary throttle, which is so designed thaty passages.

are closed as the mixture passages are opened, the air passages beingkfully closed on maximum throttle opening. i

'Further objects and advantages of the present invention will be apparent from the following description, reference beingv had to the accompanyingL drawing wherein a preferred embodimentof one form of thepresent invention is clearly shown.

In theE drawing:

Fig. 1 is aI longitudinal vertical section through a charge forming device in which the present invention is embodied.

Figs. -2 and'3 are sections on the lines 2,-2 and 3-3l of Fig. 1.v

tle.

The drawing discloses a charge forming device comprising a main air manifold 10 hav- Fig. 4 is a detailk view of the primary throtburetor unit is adapted to be attached, as shown in Fig. 1.

The carburetor unit comprises a main housing 20, having an attaching flange 22, adapted to be secured to the flange 18, by screws 24. An air inlet horn 28 is secured in position to register with an opening in the upper wall of the housing 20 in any suitable way. A casting 30, having certain dash pot cylinders and fuel passages formed therein, as will be fully described later, is secured in any suitable way to the bottom wall of the housing 20, as shown in Fig. 1, and a sheet metal fuel bowl 32`is held tight against an annular shoulderA 34'on the housing 20, by a screw 35, or in any other suitable way. Fuel is conducted fromthe main source of supply to the fuel bowl through a conduit, not shown herein,a.nd the flow offuel to the bowl iscontrolled by a float 36 operating in the usual Ymanner to maintain a substantially constant level of fuel .f therein.

Fuel flows from-the bowl 32 to a plurality of primary fuel nozzles 38,one of which is located in each of the primary mixture passages 40, the construction of .which is briefly described hereinafter. The fuel conduit ybetween the fuel bowl and the nozzles comprises a lvertical fuel passage 42, communicating atV its upper end with a vhorizontal fuel canal l44, which connects with each of the fuel nozzles through, orifices 46. Fuel is admitted from the fuel bowl to the passage l42 at all speeds through a xed metering orifice 48,

and at high speeds additional fuel is admitted through an orifice 50, controlled by a valve 52, in the manner set forth'in the above mentioned applications.

Y Fuel is lifted from the fuel bowl through the above described fuelpassages and nozzles tothemixture passages by the suction maintained therein. Closing movements of the throttle cause-a'reduction .in suction in the mixture passages which might permit. the fuel .column to Adrop sufficiently to cause a teinporary fuel starving of the engine. To prevent such an occurrence, a chechvalve 54 is provided. in an enlarged chamber 56 at the junctionof the channels 42'and 44, and on `reduction of suction inthe mixing chamber,

isf adapted to seat on an annular bead 57 formed on the bottom of the chamber 56,-tlius pi-eventingl any downward flow of fuel. Each primary fuel nozzle is provided with an open v`upper end forming a main fuel outlet and a secondary fuel outlet comprising two ori-Y fices 60 andr 62 in the side of the nozzle near thek bottom of the mixture passage. At relatively high speeds the suction in the mixture passage is enough to draw fuel from the main outlet in the top of the nozzle as well as from the orifices 60 and' 62. Atidling or low' speed operation under load, however, the suction is sufficient tolift fuel only to some. point.

between `the top of the'nozzle and orifices60 and 62, fuel Howing through these orifices by action of gravity. Each nozzle is provided with a restricted fuel metering orifice 63. The primary mixture passages 40 are parallel to each other and close together, as indicated in Figs. 2 and 3, and when the carburetor is attached to the manifold, these passages register with conduits which convey the primary mixture to the lsecondary mixing chamber, as fully described in the prior applications above referred to.

A single throttle valve 64 which extends across the primary mixture passages controls the flow therethrough and is provided with grooves 66 which register with said mixture passages. This throttle is operated by means fully disclosed in the above mentioned applications and which forms no part of the present invention; The throttle is held against'longitudinal movement by means of a screw'67 engaginga groove 69 in the periphery of the throttle. The middleprimary mixture passage registers with a tube 68, Securedin the manifoldy outlet branch 12, and which conveys the primary mixture to the secondary mixing chamber in that specific branch of theiinanifold.

As has been indicated above, the present invention relates to means for automatically regulating the mixture proportions so that the enrichment of the mixture at low and intermediate speeds is prevented while enrichment of the mixture at high speeds to 1 give the necessary power for satisfactory high speed operation can be secured. To effect this i result, a plurality of Ypassages 70 have been provided. These passages'are diagonal with respect to the primaryV mixture passages and connect the primary mixture passages with the main air chamber, Yhereinafter referred to. There are three of these passages, one'for each mixture passage 40, and said `passages terminate adjacent the primary throttle valve 64, as indicated in Fig. 1. rlhe arrangement issuch that when the throttle valve 64 occupies its closed position, as indicated in F ig. 1, the passages 70 are wide open. These passages remain wide open during operation at low Vspeed and are effective to admit sufiicient air tothe primarymixture passages at lspeeds up kto that at which the 4secondary throttle, lhereinafter described,

opening of the main air valve so as to forni a fuel mixture of substantially Iconstant proportions, as vlong as the passages 70' remain open. As wil-l be set forth more fully hereinafter, at speeds above that at which the main air throttle is opened?, there is a tendency for the mixture to become leaner and at such speeds the valve 52 isv opened to offsety this tendency. Also at speeds above that at fully open position gradually closes 'theV passages until when the throttle is in its fully open position said passages areY completely closed. The closing of these passages by the primary throttle greatly reduces the amount of air admitted tothe primary mix-V ture passages in advance of the nozzle, finally entirely preventing the admission of such air. This reduction and linal elimination of the flow of air into the primary mixture passages in advance of the nozzle is eective to create a velocity head at the nozzles 38, thus en# riching the mixture at high speeds, whichis necessary to supply the requisite power for satisfactory operation at such speeds.

Nearly all the air entering the carburetor flows through the air horn 28, controlled by a main air valve 7l, normally held against the seat 72, by a spring 74, received between the valve and a flange 76, projecting from a sleeve 7 8, slidably mounted on a stationary guide sleeve 80, fixed in the housing 20, and serving as a guide for the stem 82, to which the air valve is secured. When it is desired to choke the carburetor, the flange 76 is adapted to be lifted by an arm 88 until the upper end of the sleeve 78 engages thevalve to hold it against its seat, as fully described in the above applications,y Suiiicientair to carry the starting fuel from the nozzles to the intake ports is admitted through an elongated slot 84, formed in a plate-8G, seA cured to the housin(r 20, as shown in Fig. l.

The valve 7l admits air to a main air chamber 88 from which air flows to the primary mixture passages through anopening 90 in the floor of the air chamber and to the secondary mixing chambers through. a pase 92, which connects with the inlet of the manifold l0. A manually operable throttle 94 and a suction operated valve 95 control the flow of air through the passage 92yand the operating connection and mode of opera-V tion of such valves are fully disclosed in they copending application of Fred E. Aseltine et al., Serial No. 288,688, filed June 8,1928.

While the specilic means for operating the two throttle valves constitutes no part of the present invention, the mode of operation of these valves will be briefly set Vforth lin order to enable the present invention to be clearly understood. The valves are operated by a common operating mechanism which is so constructed that it permits the primary throttle to make a certain predetermined movement independently of the throttle 94, and a part of the movement of the primary throttle vis eifected simultaneously with the movement of the throttle 94. For instance,

during engine operation at allspeeds lower than that corresponding to a vehicular speed 01E-substantially 2O miles per hour on a level, the primary throttle is vopened and the throttle operating mechanism' is so designed thatl the throttle V94 begins to open at the speed referred to.y

It has been found that unless some compensating means is provided, the velocity through the mixture passages is great enough under substantially all operating conditions to build up a velocity head at the fuel nozzles which will effect too great a fuel flow and form too rich a mixture. To prevent this action means has previously been provided to admit air vto, the primary mixture passages posterior to the nozzles, such a structure being disclosed in copending application No. 221,37 2. This means, however, has proved only partially effective at speeds below the predetermined speed above referred to and the fuel nozzles have, therefore, been calibrated somewhat smaller than would be theoretically correct to compensate for the relatively slight velocity head created at speeds below 20 miles per hour. At greater speeds .than this, it has been found. necessary to provide other compensating means and to this end 'the air throttle 94 is provided. It has been found in practice, however, that the opening of this throttle yeffected too rapid a reduction in the velocity at the nozzles resulting in the entire elimlna- Y tion of the velocity head at a speed of about 30 miles per hour. Since the presence of some velocity head vis necessary to 'eect a proper fuel low, the mixture becomes too lean when the air throttle is opened and the valve 52 has been provided to supply additional fuel to make up for this deiciency and prevent leaning of the mixture at intermediate speeds. y

It is desirable, however, to provide an enriched mixture during operation at relatively high speeds to provide the additional power necessary for satisfactoryoperation. As stated previously, this is accomplished according to this invention by utilizing the throttle 64 to close the airpassages 7 0 as the throttle is opened, thus making use of an increased velocity head at the nozzles to enrich the mixture at high speeds. In fact, by properly designing the throttle and properly positioning the passages 70 with respect thereto, the air 'liow through passages 70 may be so restricted after` the throttle 94 begins to open as to increase the flow from the jets suliicientlyto eliminate the necessity of the valve 52. In the preferred embodiment of the invention disclosed herein, however, the primary throttle is designed to restrict the passages 70 so as to enrich the mixture at high speeds only and the valve 52 `is utilized to properly proportion the mixture for intermediate speed operation. Y

On opening of either or both the throttle within the cylinder and securedjto the lower end of the valve stem 82 in any desirable manner, as by means of a nut 104, as shown in F ig. 1. The construction of this dash pot is immate 1ial in so far as the present invention is concerned, and any known form of dash pot may be employed to control the movement of the air valve 71.

While no means for pumping additional Vfuel into the mixture passages or into the secondary air passage 92 is disclosed herein, it will be understood that any form of fuel pump, such for instance, as one of those disclosed in the above mentioned applications, may be provided if desired. It will also be understood, however,` that the presencek of such a fuel pump is immaterial so far as the present invention is concerned, and that the latter may be employed in a device havno means for pumping additional fuel f into the' mixture passage to enrich the fuel for acceleration.

A plurality of secondary mixing chambers are provided, one of which is associated with each outlet branch of the manifold and which are of identical construction. Each of these mixing chambers comprises a Venturi tube 110, provided with an external rib 112, which is clamped between the manifold and the engine bloclr when the manifold is secured to said. block, as indicated in Fig. 1. ZhenV so assembled, the outlet of the primary mixture conduit associated with said Venturi tube terminates at the point of greatest suction therein so that the Venturi tubes serve to maintain a high velocity of `How past the end of the primary mixture conduits under all'operating conditions in order to maintain a relatively high suction within said conduits. These Venturi tubes constitute no part of the present invention,but function in the manner fully set forth in the above mentioned applications.

lVhile the form of embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

That is claimed is as follows.

1. A charge forming device for internal combustion engines having in combination a plurality of mixture passages, means admitting fuel andair to each of said mixture passages, means admitting additional air to each mixture passage, and means for simultaneously varying the flow through all of said mixture passages and said means for admitting additional air so that the supply of additional air is reduced as the flow through said mixture passages is increased.

2. A charge forming device for internal combustion engines comprising a plurality of mixture passages, a plurality of supplemental air inlet passages, each of which is adapted to admit air to one of said mixture passages, and al single throttle valve for controlling the flow through all of said mixture passages and all of said supplemental air passages.

3. A charge forming device for internal combustion engines comprising a plurality of mixture passages, a Vplurality of supplemental air inlet passages, each of which is adapted to admit air to one of said mixture passages, and a single throttle valve for simultaneously increasing the area of the outlets of all of said mixture passages and decreasing the area of all of said supplemental air inlet passages.

4. A charge forming device for internal combustion engines comprising a plurality of primary mixture passages, means for supplying fuel and air to each of said mixture passages, a secondary mixing chamber into which said mixture passages deliver, a secondary air passage adapted to supply air to said secondary mixing chamber, a plurality of supplemental air passages, each of which is adapted to supply air to one of said mixture passages and means for simultaneously varying the iiow through the secondary air passage, all of said supplemental air passages and the primary mixture passages.

5. A 'charge forming device for internal combustion `engines comprising a plurality of primary mixture passages, means for supplying fuel and air to each of said mixture passages, ay secondary mixing chamber into which said mixture passages deliver, a secondary air passage adapted to supply air to said secondary mixing chamber, a plurality of supplemental air passages, each of which connects one of said primary mixture passages with the secondary air passage and means for simultaneously varying the iiow through the mixture passages and all of said air passages.

6. A charge forming device for internal combustion engines comprising a primary mixture passage, a secondary carburetor into which the primary mixture passage delivers a primary mixture of fuel and air, fuel and air inlets for said primary mixture passage, a supplemental air inlet supplying air to said primary mixture passage, a secondary air passage supplying air to the secondary carburetor, aprimary throttle in the primary mixture passage controlling the flow of mixture therethrough and the supplemental air inlet .y and means operatedl vthereby for, controlling the How through thesecondary air passage.

7. A charge forming ydevice for internal ycombustion engines comprising a primary mixture passage, a secondary carburetor into Which the primary mixture passage delivers a primary mixture of fuel and air, `fuel and air inlets for said primary mixture passage,

a supplemental air inlet supplying air to said primary mixture passage, a secondary air pas# sagesupplying air to the ysecondary carbu-l buretor, a primary throttle in the primary mixture passage controlling lthe flow of mix-v ture therethrough and the supplemental air inlet, means in the secondary air passage for controlling the iloW therethrough, and means for operating said iiow controlling means by a valve in the secondary air passage connected to the throttle for Aoperation thereby, said valve being openedV as the throttle is opened. llgA charge forming device lfor internal combustion engines comprising a primary mixturel passage, a. secondary carburetor .into

ywhich' the primary mixturepassage delivers a primary mixture of fuel and air, fuel `and air inlets'forsaid primary mixture passage,

a supplementalgair inlet supplying air to -said primary mixture passage, a lprimary throttle in the primary mixture passage adf jacent the supplemental air inlet andadapted the primary throttle to permit an increased How through the secondary air passage as the flow through the supplemental air inlet is reduced.

9. A charge forming device for internal combustion engines comprising a primary.

mixture passage, a secondary carburetor into] which the primary mixture passage delivers a primary mixture of fuel and air, fueland air inlets for said primary mixture passage,

a supplemental air inlet supplying air to said primary mixture passage, a secondary air passage supplying air to the secondary carburetor, a primary throttle in the primary mixture passage adapted to control the flow of mixture therethrough and the flow of supi pleinental air thereto, said throttle being constructed to decrease the quantity of supple mental air admitted as the flow of mixture is i increased.

10. A charge forming device for internal combustion engines comprising a primary mixture passage, a secondary carburetor into which the primary mixture passage delivers Y a primary mixture of fuel and air, fuel and air inlets for said primary mixture passage, a supplemental air inlet supplying air to said primary mixture passage, asecondary air passage supplying air to the secondary car- Y buretor, a primary throttle in the primary mixture passage adapted to close thev supple-v mental air inlet as the throttle is opened, and

`te control. the admission of air therethrough, and the volume of mixture delivered to the secondary carburetor. Y

l2. A charge forming device for internal .combustion engines comprisingy a primary Y mixture passage, a secondary carburetor into which the primary mixture passage delivers a primary'mixture of fueland air, fuel and air inlets for said primary mixture passage, a supplemental air inlet supplying air to said primary mixture passage, a primary throttle in the primary mixture passage adjacent the supplemental air inlet and adapted to close the supplemental air inlet as the primary mixture passage is opened. x

13. A Acharge forming device foi` internal combustion vengines comprising a primaryV mixture passage, aseeondarymixing cham- -berinto which the primary mixture passage delivers a primary mixture of fuel and air, fuel and air rinlets for the.` primary mixture passage, a secondary air passage supplying p air tothe secondary mixing chamber, and a supplemental.VV air passage connecting the primary mixture passage With the secondary air passage. f

14. Achargeformiiig device for internal combustion engines kcomprising a primary mixture passage, a secondary mixing chamf ber into which the primary mixture passage delivers a primarymixture of fuel and air, fueland air inlets for the primary mixture passage, a secondary airA passage supplying air tothey secondary mixing chamber, a valve inthe secondary air passage adapted to be closedunder certain operating conditions,

and a supplemental air passageconnecting y the prim ary mixture passage with the. secondaryV air passagey at ak point anterior to said valve, whereby air is admitted to the primary mixturel passagev independently of the posi- .tionof said valve. Y Y,

1 5. A charge forming device for internal combustion engines' comprising a primary mixture passage, a secondary mixing chamber into Which theprimary mixture passage delivers a primary mixture of fueland air,

fuel and air inlets for the primary mixture passage, a secondary air passage supplying l air tothe secondary mixing chamber, a supplemental air passage connecting the primary mixturefpassage with the supplemental 4mary `mixture passagepat `a position Where itfcontrols'the supplemental air passage.

. the primary mixturepassage.

16. Acharge-forming device for'internal combustion engines comprising a Vprimary 'mixture passage, a secondary mixing cham- Aberiintozivhi'cli the primary mixture passage ldelivers -aprimary mixture lof fuel and air,`A y i K cluding' a; primary throttlev for`- simultaneously varying 'theiow' 'of mixture through the 4*primary 'carburetor Alka-ndfthe flow of -air jfuel-and air' inletsffor the primary mixture passage, a secondary air passagesupplying vairto the secondaiymixing chamber, an'tair Asupplyfchainber adapted to admit air to the primary mixture passage and the *secondary air'passage, and a supplemental lairpassage connecting the secondary air' l1"?. A "charge lforming device for interna-l -;combustion engines comprising a Vvprimary j fmixturefpassage, a secondary mixing chaml ber into :which the'priinary mixture passage delivers `apriniary mixture offuel `and air, fuel "and air inlets :for the primary mixture -passage,-a-secondary airtpassage lsupplying .-air'tothe ,second-ary' mixing chamber, an `air -f' 'supplyehainber adapted t'ofsupply ,airto the secondarylair passage `and the prim-ary'mixrture passage at alltimes. 'a throttle in 'the primarymixture passage andA asupplemen- :tal lair passage adapt-ed to convey airfroin Ath'efsecond'ary*air passage Ito the 'primary `mixture passage onlywvhen the throttleisl in i' to certain positions.

18. 'A lchargefforining device for'internal combustion engines comprising a mixture passage, a lfuel :inlet therefor, an yairinlet Atherefor anterior to -said lfuel inl-et,`a by- -pass supplying airto said'mixture passage posterior /to and relatively-close to the fuel inlet, said by-,pass being of suflic'ient capacity tomateri'ally reduce the-velocity of flovvpast vthe 'fuel inlet,-and a 'restriction in the vmixture passage between V'the fuelinlet and the A 'by-pass.

19. A charge'forming-'device'for'anfinternal combustion engine having in vcombination'a mixture passage, a fuel nozzletherein, ainan airinlet admittingair to said mixture passage anterior to said 'fuel' nozzle,'a l'throttle `for said 'mixture passi-ige, a second :air inlet simultaneously adniitting'airto said passage with said second/air linletias' the throttle isfopened.

` 2l'. Acharge E"formingfdevice vfor intermary mixture' of 'fuell an'dair, and means intlirough ysaid Y supplemental and secondary Aair passages. Y

Y22. A- charge Iforming device .for internal combustion *engines comprising a lpriinaryf carburetor, fuel and-air in-lets therefor, a supplemental' air inlet for #sa-id 'primary f carbu- 'retor, asecondary'carburetor into' whichfsaid primary carburetor delivers 'a primary mixture "of fuel Aand-lair, and meansfor increas- Vvingr theY flowV of.A mixture through the primary carburetorI andthe flow. of air throughy the secondary Hair passage, While simultaneously decreasingf the flowsTv of -airv through Vthe supplemental. airf passa-ge.

Intestimony Whereof hereto aflix 'my sig- UEROME I. ANSON.

nature.

mixture jpassage vposterior tothefuelA nozzle andranterior to thejthrottle, saidthrottle'be- '.ing so constructed Yas to vary the area off the Vsecond air inlet as the throttleis movedjto vary the engine speed.

20.' A charge vforming device Jforfan I-inter- Y Vnal combustion engine having in combina y Itiona mixture passage, a fuel nozzle therein,

a mainfair inlet admitting air to said mix- A tur e:'passage anterior to said 'fuel nozzle,a throttle `for said mixture passage, a second air'inletlsimultaneously admitting air to said :mixturepassageposterior to the fuel nozzle .and anterior to r`,the throttle, said throttle 'being so constructed asto reduce the'area of 

